/enums/click_type.proto

--- v21/enums/click_type.proto  2025-10-07 23:35:20.000000000 +0000
+++ v22/enums/click_type.proto  2025-10-07 23:35:31.000000000 +0000
@@ -217,5 +217,14 @@

     // Click on a related video that navigates the user to the video watch page.
     VIDEO_RELATED_VIDEOS_CLICK = 63;
+
+    // Click on message button that navigates the user to a third-party
+    // messaging app. If the app is not installed, the ad will not show on
+    // Android, and the button will redirect to the app install page on iOS.
+    CLICK_TO_MESSAGE_THIRD_PARTY_CLICK = 64;
+
+    // Click on non-button surface of message ad that navigates the user to the
+    // Google-hosted landing page.
+    CLICK_TO_MESSAGE_LANDING_PAGE_CLICK = 65;
   }
 }